Discharge horn for liquefied fire extinguishing agent



Feb. 20, 1968 w. M. HAESSLER .ETAL

SHING AGENT DISCHARGE HORN FOR LIQUEFIED FIRE EXTINGUI Filed April 18,1966 INVENTORS. #4555451? Mz 75? M T ORNEY Unite States Patent 3,369,608DISCHARGE BURN FOR LIQUEFIED FIRE EXTINGUISHING AGENT Walter M.Haessler, Chatharn, and Ronald M. Taylor, Madison, N.J., assignors toThe Fyr-Fyter Company, New York, N .Y.

Filed Apr. 18, 1966, Ser. No. 543,192 Claims. (Cl. 16911) ABSTRACT OFTHE DISCLOSURE A discharge nozzle for fire extinguishing fluid having ahousing with a discharge horn projecting from the housing. On the closedend of the discharge horn is positioned a plate having an outwardlyturned edge which may be serrated. An inlet pipe is positioned in frontof the said plate, the inlet pipe being apertured to provide an orificeon its side facing said plate.

This invention relates to an improved method and apparatus fordischarging fire extinguishing medium.

In using carbon dioxide as a fire extinguishing agent it is generallydischarged under pressure from containers to a fire. It is importantthat the velocity of the discharge stream be reduced so that the issuingstream of carbon dioxide does not entrain air which would be carried tothe fire. Furthermore, the effectiveness of carbon dioxide as a fireextinguishing agent is increased by convetting a large portion of thedischarged fluid into carbon dioxide snow.

Early in the art a discharge device used extensively was a horn shapedmember with an orifice at its narrow end. The horn served as a shieldfor the nozzle to prevent the entrainment of air until the velocity ofthe flow had been reduced to the extent that a negligible amount of airwas entrained. Further, the back pressure in the horn resulted in theformation of a satisfactory amount of carbon dioxide snow. The dischargewhich issued from the horn was of a considerably larger diameter andmore greatly reduced in velocity than the discharge from the orifice.Such discharge horns have been satisfactory excepting that they arecumbersome because of the length and size of horn required for largecapacity discharges of carbon dioxide.

In an attempt to overcome the disadvantage of the long horn otherconstructions have been proposed such as that shown in Scott E. AllenPatent 1,993,696. In this construction a batfle member was placed aheadof the orifice so as to reduce the velocity of the discharge. In orderto provide space for the discharge of the carbon dioxide around thebaflie member the back or closed end of the horn was made of increaseddiameter.

Another construction proposed as an improvement on the Allen patent wasKucher Patent 2,547,018 in which the baflle member was made of aninverted cone and a pipe was provided from the orifice directed at theapex of the cone. The gas flow thus was around the discharge pipe andout of the wide mouth of the cone into the discharge horn of the samediameter throughout. This construction was an improvement over the Allenconstruction in that there was a heat exchange relationship between theexpanding gas and the unexpanded gas by means of the tube so that therewas believed to be a somewhat greater carbon dioxide snow production.However, under intermittent operation, in some constructions there wassome clogging from carbon dioxide snow.

The present invention aims to provide an improved method and apparatusfor discharging fire extinguishing medium.

In accordance with the invention a method and apparatus are provided inwhich the supply pipe is attached to the horn adjacent the closed endand at the side thereof. The expanded fluid is reversed in directionafter discharge through the orifice, a portion of the expanded fluidbeing directed back over the supply pipe and the extremely cold firstissuing gas, the remainder of the expanded gas being directed backoutwardly over said first portion.

The construction in accordance with the invention is advantageous inthat the distance required by the discharge pipe and the horn is shorterthan that heretofore required.

Another object of the invention is to provide an improved method fordischarging fire extinguishing medium which does not cause carbondioxide snow clogging of the discharge nozzle even under intermittentoperation.

Another object of the invention is to provide an improved apparatus fordischarging fire extinguishing medium which is simple and economical inmanufacture, efiicient in operation, and durable in use.

Other objects and advantages of the invention will be apparent from thefollowing description and from the accompanying drawing which shows, byway of example, an embodiment of the invention.

In the drawing:

FIGURE 1 is a vertical cross sectional view of the discharge nozzle inaccordance with the invention.

FIGURE 2 is an end view of the construction of FIG- URE l as viewed inthe direction of the arrows 2-2.

Referring .to the drawing there is shown in FIGURE 1 a vertical crosssectional view of a discharge nozzle 1 in accordance with the inventionand including a housing 2, an inlet pipe or tube 3 and a discharge horn4. A deflector member 5 provides first deflecting means 6 and seconddeflecting means 7. The housing 2 may have its outer surface made offlattened surfaces for engagement by a wrench. A passage 8 extendsthrough the housing 2. The passage 8 is reduced in size at one end asindicated at 9 and of increased diameter adjacent thereto to provide ashoulder it The passage 8 outwardly of the shoulder It is still furtherincreased in diameter as indicated at 11 and made with a threadedsurface 12 for attachment to a piping system.

The inner end of the housing 2 is turned over as indicated at 13 toprovide means for firmly holding the discharge horn 4 in position.Further, if desired, a weld may be made as indicated at 14. The inletpipe 3 is provided with an enlarged end 15 adapted to abut against theshoulder 19. A hole or other suitable marking means may be made asindicated at 16 to provide visual indication of the proper position ofthe inlet pipe 3 as will appear later. The inlet pipe 3 is retained inposition in the housing 2 by a force fit between its enlarged end 15 andthe adjacent inner wall 11 of the housing 2. As may be seen from thedrawing the inlet pipe 3 is spaced from the circular plate or deflectormember 5 by a distance less than the outer diameter of said inlet pipe.

Orifice means 29 is provided on the side Wall of the inlet pipe 3 at aposition along the length of the pipe centrally of the discharge horn 4,and in line with the marking hole 16. The inlet pipe 3 is provided witha closed end 21, the pipe extending beyond the orifice 20 to provide aspace 22 wherein may be entrapped dust or particles which may be carriedwith the gas and which might interfere with the flow of carbon dioxidethrough the orifice 20.

The discharge horn 4 is provided with a closed end wall 25 and an openend 26. The diameter of the open end 26 is preferably somewhat largerthan the diameter of the closed end 25. The drawing is quite accuratewith respect to the size and proportions of a working model.

The deflector member 5 is preferably formed of a circular plate formingthe first deflecting means 6 having its edge turned out approximately atright angles to the plane of the plate 6 as indicated at 27 forming thesecond deflecting means ,7. The turned out edge 27 may be serrated so asto form notches 29 and teeth 30. Generally the base width of the notches29 of the serrated edge 27 is greater than the base width of the teeth30. In alternative constructions, for example, if the discharge horn 4is reduced in size while the orifice and supply tube are maintained atthe same size, it may be found advantageous to omit alternative teeth30. The deflector member 5 may be secured in position against the endwall 25 by rivets 31 and 32., In an alternative construction thedeflector member 5 might be made of a section of cylinder welded orotherwise suitably attached to the end wall 25 in which event the firstdeflecting means would be provided.

by the inner surface of the end wall 25. In assembling the nozzle 1, themarking hole 16 of the inlet pipe 3 enlarged end is placed towards theend Wall there by assuring that the orifice 20wil1 be properlypositioned opposite the first deflecting means 6.

In testing commercial constructions in accordance with the invention ithas been found that the spacing between the orifice and the spreadershould be maintained rather closely to the proportions shown in thedrawing even though the diameter of the nozzle is varied to providedifferent rates of discharge. While the inlet pipe 3 might be terminatedjust shortly after the orifice 20 it is preferable that it be extendedas shown.

In practicing the method in accordance with the invention a fireextinguishing medium liquefied under pressure is discharged through theorifice 20 thereby allowing the fluid to expand while it is directed toimpinge against the center of the deflecting means 6 so that the fluidis radially dispersed at practically right angles to its issuingdirection. A portion of the dispersed fluid impinges against the turnedout edge 27 and the teeth 30 which provide a second deflecting meanscausing a first portion of the radially dispersed expanded fluid to flowback over itself and over the inlet pipe 3 in a heat exchangerelationship, the remainder of the radially dispersed expanded fluidbeing directed outwardly by the discharge horn 4. The issuing expandedgas and carbon dioxide snow issuesat a uniform rate from, the open end26 of the horn 4.

While the invention has been described and illustrated with reference toa specific embodiment thereof, it will be understood that otherembodiments may be resorted to without departing from the invention. Forexample, the method of the invention might be practiced by the use of aconstruction in which the inlet pipe is arranged to enter through theopen end of the discharge horn, in which event the orifice would bepositioned in the end of the inlet pipe. Therefore, the form of theinvention set out above should be considered as illustrative and not aslimiting the scope of the following claims.

We claim:

1. A discharge nozzle for fire extinguishing fluid liquefied underpressure comprising a housing having an inlet, an inlet tube carried bysaid housing at said inlet,

discharge orifice means being an aperture through the turnedapproximately at right angles to the plane of the plate, said platelocated on the end wall of said discharge horn and spaced from saidorifice, means and positioned at approximately right angles thereto.

2. A discharge nozzle according to claim 1 in which the inlet tube ispositioned with its axis parallel to the plane of said circular plate.

3. A discharge nozzle according to claim 1 in which said inlet tube isspaced from said circular plate by a distance less than the outerdiameter of said inlet tube.

4. A discharge nozzle according to claim 1 in which said inlet tubeextends beyond its orifice so that the end wall of said tube ispositioned outwardly of the edge of said circular plate.

5. A discharge nozzle according to claim 1 in which said turned edge ofsaid plate is serrated.

References Cited UNITED STATES PATENTS M. HENSON WOOD, JR., PrimaryExaminer.

VAN C. \UILKS, Assistant Examiner.

